Operation CHARM: Car repair manuals for everyone.

With Powertrain Control Module (PCM)

Diagnostic Trouble Code (DTC) 43 sets if there is an open or short to ground in the circuit. Refer to Diagnostic Trouble Code Charts. Under Computer and Controls/System Diagnosis/Procedures. Testing and Inspection

If the conditions for DTC 43 are present, the scan will always display "YES." There should not be a knock at idle unless an internal engine problem, or a system problem exists.